Sun, 14 Jan 2001

The dangers of flying over Irian

By I. Christianto and Pandaya

JAKARTA (JP): Imagine this. You are one of nine people flying a light plane over the virgin jungle of mountainous Irian Jaya. It is your maiden voyage by plane over the territory notorious amongst many high flyers for its rough mountainous terrain, unpredictable weather patterns and untouched wilderness.

While the light plane undertakes roller coaster type maneuvers between perpendicular ravines at 10,000 feet, a rainstorm suddenly looms large ahead. What would your pilot possibly do? If he is wise and well-versed with the topography and weather patterns of Irian Jaya, he would make a U-turn and head straight for a nearby airstrip or the airport of origin.

It is these natural features that have been blamed for the recent crash on Trikora Peak, Jaya Wijaya regency, of the Navy's CASA NC 212 that killed all nine people aboard. The wreckage was found scattered at the height of 11,800 feet (3,597 meter) where temperature was minus five degrees Celsius.

For daredevil pilots, Irian Jaya with its airstrips and small airports lacking in adequate facilities it is an exciting airspace to satisfy their adventurous spirits. But for people unfamiliar with the area, flying a plane there would most probably send a chill down their spine.

The Irianese mountain peaks and steep slopes that one has to pass through when flying from Timika in the south to the north eastern capital of Jayapura are particularly "challenging" for lesser-experienced pilots in Irian Jaya.

There are hundreds of peaks with near perpendicular walls that light planes would find difficult passing through, especially when it is cloudy or rainy. Tropical Irian Jaya is highly humid with an annual average rainfall of 5,500 millimeter.

Light planes have become the only mode of transportation to connect outlying areas of the sparsely populated province in the absence of roads and presence of rivers which can only be obviously used for water transport.

Seasoned pilots of light planes familiar with flying a plane in Irian Jaya have thrilling and stomach-churning Hollywood-style stories to tell.


Djoko Toret, 45, is a senior pilot of state-owned Merpati Nusantara Airlines, who used to be based in Biak between 1980 and 1990 to serve feeder routes in the region. As part of its social mission, Merpati serves both feeder and commercial routes.

"From the western tip town of Sorong, until the center of the island, there is a mountain range. Peaks stand close to each other and weather is unpredictable, making flights risky," Djoko, who flew a Twin-Otter plane, told The Jakarta Post.

Light planes like Twin Otters are seen as the best choice in Irian Jaya because the aircraft can take off and land on very simple airstrips.

As this sort of plane doesn't have a sophisticated navigation system, don't have even consider becoming a pilot in Irian Jaya if you didn't first have a very good visual ability.

The pilot has to be constantly on the look out for changing weather patterns and topography, mountains, gaps and valleys. The "check points" are often deceptive because gaps and ravines look similar.

"On many occasions we have to fly through ravines or spaces between mountains to reach destinations. A slight mistake may end up in the plane hitting a mountainside," Djoko said.

For instance, he said, there are two routes when flying from the mining city of Timika in the southwest of Irian Jaya, to Wamena, the capital of Jayawijaya district.

One is via the Enarotali Lake and Baliem Valley, and the other is via the South gap. The latter route is much more challenging as the flight must follow a mountainous line and there are many identical gaps.

According to Djoko, the Timika-Jayapura route is especially tough.

"I am greatly sympathetic to the recent incident on the Navy CASA NC-212 aircraft. But I think every pilot flying in the Irian region must have gained equally special training and exercises as I managed to get in Merpati," he said.

Wreckage of the ill-fated 16-seat Casa NC-212 turbo-prop was found by two pilots of the Mission Aviation Fellowship (MAF), Harry Berghuis and Tom Hans, who flew a Bell Jet Ranger 201.

The cause of the crash is not yet entirely clear. The plane's pilot Maj. Sutopo Waluyo, a deputy chief of Squadron 600 and co- pilot First Lt. Deddy Haryanto, were believed to be very experienced as they had been posted in Irian Jaya for about six years.

It is believed that the CASA aircraft took the wrong gap when it attempted to enter Wamena from the South Gap, where there are numerous gaps with similar features.

MAF has long become the backbone of air transport in the Irian Jaya hinterland.

A German-born MAF pilot, Alexander Bruecki, 31, told Kompas that pilots serving in Irian Jaya should have good knowledge of the ever-changing weather there.

Bruecki, who flies a Cessna and usually carries three to five missionaries and locals, has spent five years in different parts of Irian Jaya.

MAF has six foreign pilots and one Irian man for its nine fleet of nine planes. Fellowship officials apply strict rules for the planes' maintenance. Every aircraft undergoes thorough checks after 50-100 hours of flying.

The Casa NC-212 plane was made by Bandung-based PT Dirgantara Indonesia (previously IPTN) in collaboration with CASA of Spain. The ill-fated plane was manufactured some 16 years ago. Prior to this incident, five other Casa aircraft of that type have crashed at various locations in the country.


For Djoko, the high and numerous mountain peaks are not the major challenge. The real danger is the quick changing weather.

Whenever rain starts to falls or thick clouds or fog suddenly appear, the pilot has to quickly ascend and fly higher to a safer altitude for better vision, he said.

The pilot is then able to decide whether the plane can proceed to its destination or not. To return without ascending would not be possible as the plane might be trapped in a narrow gap.

"I have often faced a sudden change in weather conditions. It suddenly starts to rain or I become trapped in clouds," he said.

Bad weather is usually most disruptive when he is flying low.

Light planes are usually not pressure resistant. Light planes like Casa NC-212, Twin Otters, Cessnas are not usually well equipped with enough oxygen when flying at higher altitudes. Normally, light planes fly at an altitude of between 8,000 feet and 10,000 feet, though the engines allow flying to occur up to 25,000 feet.

According to Djoko, taking off and landing on most runways in Irian Jaya was also a great challenge. The load has to be calculated carefully according to the size of the runway at the place of destination.

Residents of Irian Jaya, he said, remember fondly one incident when they had to voluntarily pull out a plane trapped in a swamp after landing.

Throughout his 10-year assignment in Irian Jaya he has enjoyed warm relations with locals.

"I have learned that flight is the only means of transportation, but it is not possible to impose even higher fares for them as they don't earn high wages. They are mostly small traders, teachers, civil servants and social workers who need transportation," he said.

Light planes like the Casa NC-212, Twin Otter, Cessna are most suitable for most runways in Irian Jaya which are only about 600 meters long.

There are some 40 runways in Irian Jaya.

Captain Wuri Septiawan, also of Merpati, advises that aircraft operating in Irian must get proper maintenance.

"Technology wise, a Casa NC-212 plane is equipped with radar, radio altimeter and so on. But when there are many passengers, the plane is not able to ascend as it is not cabin-pressurized," he said.

Bad weather has caused several plane crashes. Accidents in Irian Jaya have involved a medium-body aircraft Fokker-28 of MNA in July 1993 and HS748 of Bouraq in August 1995.